这个功能在未来可能会被sql server取消，官网建议用check constraint功能作为代替了

1. rules

• Rules are cousins to constraints
• Rules are created as a general constraint to be applied to various tables
• Used instead of creating individual constraints for each table

2.How to Use Rules

• Rules are created in their own syntax using a create statement

Create Rule RuleName�as�<Expression>

After rules are created, they must be bound to a column in a table
1 rule per column in a table

Sp_bindrule RuleName,�‘TblName.Column’